dest6.c revision 171259 
1/*	$FreeBSD: head/sys/netinet6/dest6.c 171259 2007-07-05 16:23:49Z delphij $	*/
2/*	$KAME: dest6.c,v 1.59 2003/07/11 13:21:16 t-momose Exp $	*/
3
4/*-
5 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 * 1. Redistributions of source code must retain the above copyright
12 *    notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 * 3. Neither the name of the project nor the names of its contributors
17 *    may be used to endorse or promote products derived from this software
18 *    without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include "opt_inet.h"
34#include "opt_inet6.h"
35
36#include <sys/param.h>
37#include <sys/systm.h>
38#include <sys/malloc.h>
39#include <sys/mbuf.h>
40#include <sys/domain.h>
41#include <sys/protosw.h>
42#include <sys/socket.h>
43#include <sys/errno.h>
44#include <sys/time.h>
45#include <sys/kernel.h>
46
47#include <net/if.h>
48#include <net/route.h>
49
50#include <netinet/in.h>
51#include <netinet/in_var.h>
52#include <netinet/ip6.h>
53#include <netinet6/ip6_var.h>
54#include <netinet/icmp6.h>
55
56/*
57 * Destination options header processing.
58 */
59int
60dest6_input(struct mbuf **mp, int *offp, int proto)
61{
62	struct mbuf *m = *mp;
63	int off = *offp, dstoptlen, optlen;
64	struct ip6_dest *dstopts;
65	u_int8_t *opt;
66
67	/* validation of the length of the header */
68#ifndef PULLDOWN_TEST
69	IP6_EXTHDR_CHECK(m, off, sizeof(*dstopts), IPPROTO_DONE);
70	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
71#else
72	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, sizeof(*dstopts));
73	if (dstopts == NULL)
74		return IPPROTO_DONE;
75#endif
76	dstoptlen = (dstopts->ip6d_len + 1) << 3;
77
78#ifndef PULLDOWN_TEST
79	IP6_EXTHDR_CHECK(m, off, dstoptlen, IPPROTO_DONE);
80	dstopts = (struct ip6_dest *)(mtod(m, caddr_t) + off);
81#else
82	IP6_EXTHDR_GET(dstopts, struct ip6_dest *, m, off, dstoptlen);
83	if (dstopts == NULL)
84		return IPPROTO_DONE;
85#endif
86	off += dstoptlen;
87	dstoptlen -= sizeof(struct ip6_dest);
88	opt = (u_int8_t *)dstopts + sizeof(struct ip6_dest);
89
90	/* search header for all options. */
91	for (optlen = 0; dstoptlen > 0; dstoptlen -= optlen, opt += optlen) {
92		if (*opt != IP6OPT_PAD1 &&
93		    (dstoptlen < IP6OPT_MINLEN || *(opt + 1) + 2 > dstoptlen)) {
94			ip6stat.ip6s_toosmall++;
95			goto bad;
96		}
97
98		switch (*opt) {
99		case IP6OPT_PAD1:
100			optlen = 1;
101			break;
102		case IP6OPT_PADN:
103			optlen = *(opt + 1) + 2;
104			break;
105		default:		/* unknown option */
106			optlen = ip6_unknown_opt(opt, m,
107			    opt - mtod(m, u_int8_t *));
108			if (optlen == -1)
109				return (IPPROTO_DONE);
110			optlen += 2;
111			break;
112		}
113	}
114
115	*offp = off;
116	return (dstopts->ip6d_nxt);
117
118  bad:
119	m_freem(m);
120	return (IPPROTO_DONE);
121}
122